The exposed jaw is projected image. Wayne is actually 4' 2" and rests deep in the super suit. The jawline is a projection, a video on a microfilm of a tough guy talking. Also the reason why Wayne is never assumed to be the Batman; he's too short. Most of his villains knew this, especially Penguin.
I see Batman as a mech power armor super soldier before his time.
Shoot the guy in the jaw, go ahead. It will bounce off the metal underlay. Call my conjecture Ad Hoc Neo Canon, my hand out for royalties. Wait, DC has no money. Should have figured out Iceman Cometh or Dead Limpid Pool. The Mouse has all the cash.
Chatting on supers is so nerdlinger. I owe you both a weggie.